Objective To evaluate the clinical efficacy and antimicrobial resistance cost of low-dose erythromycin given for 12 months to patients with non-CF bronchiectasis with a history of frequent pulmonary exacerbations.

Design, Setting, and Participants Twelve-month, randomized (1:1), double-blind, placebo-controlled trial of erythromycin in currently nonsmoking, adult patients with non-CF bronchiectasis with a history of 2 or more infective exacerbations in the preceding year. This Australian study was undertaken between October 2008 and December 2011 in a university teaching hospital, with participants also recruited via respiratory physicians at other centers and from public radio advertisements.

Conclusion and Relevance Among patients with non-CF bronchiectasis, the 12-month use of erythromycin compared with placebo resulted in a modest decrease in the rate of pulmonary exacerbations and an increased rate of macrolide resistance.Trial Registration anzctr.org.au Identifier: ACTRN12609000578202